#include <stdio.h>

#define N 1000

int catalan(int n)

{

    if(n == 1) return 1;

    int sum;

    sum = catalan(n - 1) * (4 * n - 2) / (n + 1);

    return sum;
}

int main()

{

    int n;

    while (scanf("%d", &n), n)

        printf("%d\n", catalan(n));

    return 0;
}